Andrew Warren is sought by US police. A spokesman at the college he works at said colleagues were ‘shocked to learn of the case’.
Photograph: Chicago Police Department/PA

An Oxford University college has urged one of its employees to hand himself in as police investigating a murder in the US say they are closing in on him and an American academic also suspected of involvement.

The call came as the victim’s mother, Charlotte Cornell, spoke out about her son’s murder. “Our family is deeply saddened by the death of our son. It is our hope that the person or persons responsible for his death are brought to justice,” she told the Associated Press from her home in Michigan, where Cornell-Duranleau grew up.

Warren’s colleagues at Somerville urged him to get in touch with the local authorities, regardless of the circumstances, “in the best interests of everyone concerned”. A spokesman said they were “shocked to learn of the case”.

Writing on the college’s website on Thursday its principal, Alice Prochaska, said staff were only recently made aware of the case, which she said was “clearly extremely worrying”. She added: “We and the university authorities will liaise with the investigating authorities and provide any assistance that is required. This comes as upsetting news to all of us.”

Local police believe they have an “idea of their whereabouts”. Anthony Guglielmi, a spokesman, said: “Our primary focus is to facilitate a safe surrender and we strongly encourage Professor Lathem and Mr Warren to do the right thing.”

Local media also reported that the two men drove about 80 miles (129km) north-west of Chicago after the murder and donated $1,000 (£761) in the victim’s name to the Lake Geneva public library.

According to the Associated Press another police spokesman, Frank Giancamilli, characterised the attack as “domestic in nature”, but declined to discuss the possible motive in further detail. The attack was so violent that the blade of the knife believed to have been used to kill Cornell-Duranleau was broken, Guglielmi added.

Warren, 56, oversaw pensions and payrolls at Somerville. Chicago police believe he was visiting the US from his home in England for the first time and arrived recently. Lathem, 42, is believed to have known the victim, though it is not known how.

The police have placed restrictions on both men’s passports that prevent them from leaving the US and have said they are “to be considered armed and extremely dangerous”. The two men were last seen getting into a grey 2007 Hyundai.

Officers said the victim, who lived in Chicago, was found with multiple stab wounds in the 10th-floor apartment near the city centre at about 8.30pm on 27 July. He was pronounced dead at the scene.

Court files give Warren’s address as the Oxford college but he says on Facebook that he lives in Swindon, Wiltshire, and is a former cashier and driver for Stagecoach.

Lathem has worked at Northwestern since 2007 and specialises in the bacteria that caused the bubonic plague. The university said he had been placed on leave and banned from entering the campus.